I've been running a server for a few days, and already most all the players have quantum leggings. Unfortunately, that means everyone is running around at light speed and there is absolutely no need for boats or minecarts ever (carts were also indirectly received a nerf with the new sprint feature). Even if there is an already ready to go minecart track with minecart it's still faster to just run with ctrl. Even with using ctrl almost 100% of the time the energy usage is still minuscule.
I would suggest that the quantum leggings use far more energy and/or not go so fast. The suit's sprint feature should be something you use only in an emergency or if you are willing to burn through a lot of energy. You should prefer to still take a fast minecart to a destination and save energy instead of just ctrl-ing everywhere without thought.
The rest of the suit's energy use is probably too low as well.